#include <iostream>
#include "Integer.h"
using namespace std;

int main()
{
	BIG fib=1, t0=0, t1=1;
	int i;
    for(i=2; fib.digits()<1000; i++)
    {
        t0 = t1;
        t1 = fib;
        fib = t0+t1;
    }
	cout << i << endl;
	return 0;
}
